1/7. dermatofibrosarcoma protuberans harboring t(9;22)(q32;q12.2).More than 20 cases of dermatofibrosarcoma protuberans (DFSP) exhibiting chromosomal abnormalities have been reported. Approximately three fourths of these tumors have harbored supernumerary ring chromosomes, which have been suggested to be specific for this tumor. However, a small number of DFSPs with translocations such as t(2;17), t(X;7), and t(17;22) have recently been reported. We report a DFSP arising in a 23-year-old woman which unexpectedly exhibited the balanced translocation, t(9;22)(q32;q12.2) as the only anomaly with G-band technique. Dual-color fluorescence in situ hybridization (FISH) confirmed these cytogenetic findings. Similar to that previously reported for DFSPs with translocations, the present tumor also lacked ring chromosomes.- - - - - - - - - - ranking = 1keywords = hybridization (Clic here for more details about this article) |
2/7. Supernumerary ring chromosome in a Bednar tumor (pigmented dermatofibrosarcoma protuberans) is composed of interspersed sequences from chromosomes 17 and 22: a fluorescence in situ hybridization and comparative genomic hybridization analysis.cytogenetic analysis of Bednar tumor (pigmented dermatofibrosarcoma protuberans) has not been reported previously. Here, we report the identification of a supernumerary ring chromosome in a Bednar tumor by chromosome painting with fluorescence in situ hybridization (FISH) and comparative genomic hybridization (CGH). chromosome painting with FISH demonstrated that the supernumerary ring chromosome was composed of discontinuous, interwoven sequences from chromosomes 17 and 22. Amplification of chromosomes 17 and 22 sequences was confirmed by CGH. These results indicate that Bednar tumor and dermatofibrosarcoma protuberans are characterized by the same chromosomal features. To our knowledge, this is the first report that the ring chromosome in Bednar tumor is composed of amplified material from chromosomes 17 and 22.- - - - - - - - - - ranking = 10keywords = hybridization (Clic here for more details about this article) |
3/7. Supernumerary ring chromosomes in dermatofibrosarcoma protuberans may contain sequences from 8q11.2-qter and 17q21-qter: a combined cytogenetic and comparative genomic hybridization study.dermatofibrosarcoma protuberans (DFSP) presents with characteristic cytogenetic features such as reciprocal t(17;22)(q22;q13) or, more commonly, supernumerary ring chromosomes containing sequences from chromosomes 17 and 22. Here, we report the identification of a novel abnormality in a 43-year-old woman with DFSP. cytogenetic analysis of tumor cells showed the presence of a supernumerary ring chromosome as the sole anomaly. Amplification of 8q11.2 approximately qter and 17q21 approximately qter sequences was confirmed by comparative genomic hybridization (CGH); the present case apparently lacked amplification of chromosome 22. To our knowledge, this is the first case indicating that the ring chromosome in DFSP is possibly associated with amplified material from chromosomes 8 and 17.- - - - - - - - - - ranking = 5keywords = hybridization (Clic here for more details about this article) |
4/7. Sustained complete remission of metastatic dermatofibrosarcoma protuberans with imatinib mesylate.dermatofibrosarcoma protuberans (DFSP) is a soft tissue tumor which may recur locally and rarely causes metastases to vital organs. DFSPs have specific chromosomal abnormalities involving the platelet-derived growth factor beta-chain locus (PDGFB) which may render these tumors responsive to targeted therapy with the tyrosine kinase inhibitor imatinib mesylate. A patient with locally recurrent and metastatic DFSP resistant to first-line chemotherapy was treated with imatinib mesylate 400 mg/day. The tumor was examined by a novel fluorescence in situ hybridization (FISH) method for specific rearrangements of the PDGFB locus. The patient was followed for response and toxicity by physical examination and imaging studies. FISH revealed PDGFB rearrangement indicative of multiplication of the PDGFB fusion locus within a ring chromosome. physical examination showed response within the first month of treatment, and subsequent computed tomography and fluorodeoxyglycose positron emission tomography documented complete response to imatinib therapy. Our patient is now in sustained complete remission for 20 months with minimal toxicity. We conclude that sustained complete remission of metastatic DFSP with specific FISH abnormalities involving the PDGFB locus can be obtained with imatinib mesylate with minimal toxicity for the patient.- - - - - - - - - - ranking = 1keywords = hybridization (Clic here for more details about this article) |
5/7. COL1A1-PDGFB fusion in a pediatric Bednar tumor with 2 copies of a der(22)t(17;22).We present a 10-year-old girl with a pure Bednar tumor (pigmented dermatofibrosarcoma protuberans) of the right shoulder. cytogenetic analysis demonstrated 47 chromosomes with 2 copies of a derivative chromosome 22, der(22)t(17;22)(q22;q13). fluorescence in situ hybridization (FISH) analysis demonstrated the COL1A1-PDGFB fusion on both der(22) chromosomes. By RT-PCR and sequencing, we observed a fusion of the COL1A1 exon 41 with PDGFB exon 2. This pure pediatric Bednar tumor in a child, like childhood dermatofibrosarcoma protuberans, had a linear structural abnormality rather than a ring chromosome that is more commonly encountered in adult Bednar and dermatofibrosarcoma protuberans tumors. The underlying molecular abnormality in this pediatric Bednar tumor is the same as in dermatofibrosarcoma protuberans.- - - - - - - - - - ranking = 1keywords = hybridization (Clic here for more details about this article) |
6/7. Involvement of chromosomes 17 and 22 in dermatofibrosarcoma protuberans.literature on the cytogenetics of dermatofibrosarcoma protuberans (DFSP) is limited; only 10 cases with chromosome aberrations have been reported. They are karyotypically characterized by the presence of supernumerary ring(s), either as the sole cytogenetic abnormality or together with a few additional structural or numerical changes. We report the cytogenetic and fluorescence in situ hybridization (FISH) analysis of three new DFSP, one primary and two recurrent tumors. In two cases we found a supernumerary ring as the sole change, whereas the third had two copies of a marker chromosome and monosomy of chromosome 22. Sequences of chromosomes 17 and 22 were identified by FISH in the supernumerary rings and in the markers. The fluorescence pattern suggested that additional sequences were present in the two rings, but showed that the marker chromosomes were entirely painted by chromosome 17 and 22 probes. The findings indicate that juxtaposition and/or amplification of chromosome 17 and 22 sequences could be crucial in the pathogenesis of DFSP.- - - - - - - - - - ranking = 1keywords = hybridization (Clic here for more details about this article) |
7/7. Supernumerary ring chromosomes containing chromosome 17 sequences. A specific feature of dermatofibrosarcoma protuberans?Mystery surrounds the mechanisms by which the uncommon cutaneous tumor dermatofibrosarcoma protuberans (DP) arises and progresses. A clue may be at hand in the form of extra abnormal chromosomes (one of three ring chromosomes per case with or without other chromosome abnormalities) seen in some 10 cases, including five cases in our experience. The specificity of the rings to DP would be enhanced if the rings were found to contain a contribution from a constant chromosome. We here report fluorescence in situ hybridization (FISH) results bearing on the chromosomal content of DP rings, together with clinical, pathologic, and cytogenetic documentation of our first two cases, which were briefly reported earlier, and three new DP cases. To dissect a translocation (in our 2nd case), we probed by FISH and discovered chromosome 17 sequences in the rings in all five DP cases. Nonfluorescent bands were seen on some rings painted with a whole chromosome 17 probe, indicating the presence in these rings of foreign chromosome sequences. The complexity of the rings was underscored by the detection in only one case of chromosome 17 centromeric sequences. The situation in DP seems to have parallels to that in well-differentiated liposarcoma, another tumor of intermediate malignancy with extra abnormal marker chromosome containing contributions from a constant chromosome and variable donors. In DP the supernumerary rings are clearly specific and significant.- - - - - - - - - - ranking = 1keywords = hybridization (Clic here for more details about this article) |